Massachusetts Planting Zones by City and ZIP Code
Massachusetts runs from zones 5b to 7b; 42% of its ZIPs are 6b, Boston is 7a and Worcester is 6a.
Massachusetts runs from zones 5b to 7b
The coldest night of the winter averages -15°F to -10°F in the coldest of Massachusetts’s ZIP codes and 5°F to 10°F in the warmest. Most of the state is zone 6b.
Planting zones of Massachusetts cities
| City | Zone | Coldest night, on average | Since 2012 |
|---|---|---|---|
| Boston02108 | 7a | 0°F to 5°F | half a zone warmer than 2012 (6b) |
| Worcester01608 | 6a | -10°F to -5°F | half a zone warmer than 2012 (5b) |
| Springfield01103 | 6b | -5°F to 0°F | half a zone warmer than 2012 (6a) |
| Pittsfield01201 | 5b | -15°F to -10°F | same as 2012 |
| Hyannis02601 | 7a | 0°F to 5°F | same as 2012 |
| Lowell01852 | 6b | -5°F to 0°F | half a zone warmer than 2012 (6a) |
Tap a ZIP for that address’s frost dates and this month’s jobs.
Find your zone anywhere in Massachusetts
A ZIP code or a town gives you its zone, how it moved since 2012, the frost dates at the nearest NOAA station, and the jobs for this month timed from them.
What to plant in Massachusetts this month
The calendar for each of Massachusetts's main zones, from vegetables to pruning and winter protection, each job tied to the extension page it comes from. Pick a month, or read the whole year below it.
Timed from the median frost dates of the 29 NOAA stations in Massachusetts’s zone 6b: last spring frost Apr 26, first fall frost Oct 15. Your own ZIP’s frost dates move every window, so the ZIP tool times them for you.
Pick a month above to see every job in it.
The year at a glance
- Start vegetable seeds indoorsJan to Apr
- Sow vegetables in the gardenMar to May
- Sow the fall vegetable gardenJun to Aug
- Set out transplantsMar to May
- Plant trees and shrubsMar 15 to May 10 and Oct 1 to Nov 19
- Plant garlicOct 1 to Nov 5
- Plant tulips and other spring bulbsOct 22 to Oct 29
- Divide fall-blooming perennialsApr 5 to May 17
- Divide spring and summer-blooming perennialsSep 3 to Oct 15
- Prune trees and summer-flowering shrubs while dormantFeb 15 to Mar 29
- Prune spring-flowering shrubs after they bloomApr 12 to Jun 7
- Water evergreens and new plantings until the ground freezesSep 17 to Nov 26
- Mulch perennial crowns once the ground freezesNov 26 to Dec 10
- Pull back the winter mulchMar 8 to Mar 22
- Put hardware cloth around young tree trunksOct 15 to Nov 26
- Dig and store dahlia and gladiolusOct 15 to Oct 22
- Cut back perennials after a hard freezeOct 22 to Nov 19
What changed in Massachusetts since 2012
Every ZIP on both mapsCompared ZIP by ZIP from the 2023 and 2012 USDA tables; 675 Massachusetts ZIP codes appear in both.
Why Massachusetts’s zones moved
Of the cities above, Boston went from 6b to 7a, Worcester went from 5b to 6a, Springfield went from 6a to 6b and Lowell went from 6a to 6b.
The USDA explains the national picture: “When compared to the 2012 map, the 2023 version reveals that about half of the country shifted to the next warmer half zone, and the other half of the country remained in the same half zone.” The new map uses 1991 to 2020 and more than 13,000 weather stations, so it draws Massachusetts’s hills, valleys and cities more finely than the 2012 map did.
A warmer zone changes which perennials and shrubs come through the winter, not when the garden gets planted; that still follows the frost dates.

Frost dates and seed starting in Massachusetts
Massachusetts planting zone questions
Planting zones by state
Sources. USDA Plant Hardiness Zone Map, ZIP code tables (2023 and 2012), PRISM Climate Group, Oregon State University; USDA Plant Hardiness Zone Map; USDA Unveils Updated Plant Hardiness Zone Map (USDA Agricultural Research Service, November 15, 2023); NOAA NCEI U.S. Climate Normals 1991-2020, annual/seasonal, by station (v1.0.1); NC State Extension Gardener Plant Toolbox. Zones are read from the PRISM ZIP code tables, read Oct 9, 2026; a ZIP code’s zone is the zone at its center. The calendar’s extension sources are listed on the planting zones page and under each job.